Noncoding RNAs As Prognostic Markers And Therapeutic Targets In Breast Cancer
Funder
National Health and Medical Research Council
Funding Amount
$550,283.00
Summary
Normal human development involves a symphony of genetic changes that control the growth and differentiation of different types of cells during embryogenesis. For many years it has been assumed that most genetic information is transacted by proteins, and that the remaining 98% of the human genome that does not encode proteins was (apart from a limited amount of associated regulatory elements) largely non-functional evolutionary junk. However, this may not be the case. Recent results from our labo ....Normal human development involves a symphony of genetic changes that control the growth and differentiation of different types of cells during embryogenesis. For many years it has been assumed that most genetic information is transacted by proteins, and that the remaining 98% of the human genome that does not encode proteins was (apart from a limited amount of associated regulatory elements) largely non-functional evolutionary junk. However, this may not be the case. Recent results from our laboratory and others have shown that most of our genome and that of other mammals is actually expressed as noncoding RNA, which appears to be developmentally regulated. These RNAs (of which there appear to be tens of thousands, well outnumbering the protein-coding mRNAs) have been referred to as the hidden layer or dark matter of our genome, as they have barely been studied, but appear to play a central role in both normal and abnormal development in humans. There is now increasing evidence that many noncoding RNAs, including small regulatory RNAs called microRNAs, are perturbed in cancer and that these perturbations may be directly involved in, and be an accurate indicator of, cancer state and the direction of cancer progression. If this is true we need to understand the expression and functions of these RNAs in order to develop better diagnostics and perhaps powerful new therapeutics for cancer, based on RNA technology and generic delivery systems. This project will explore the patterns of noncoding RNA expression in normal breast development and in breast cancer, to identify those RNAs that direct or accompany the differentiation of these tissues, and to test the effects of interfering with their expression on these processes. These foundation studies lie at the leading edge of a new understanding of human genetics and cancer, and will provide a platform for future applications in medicine that utilize this information and understanding.Read moreRead less
Genetic Variation Of Mitochondrial Complex I: Its Role In Rare And Common Diseases
Funder
National Health and Medical Research Council
Funding Amount
$628,415.00
Summary
Our bodies convert food into energy in tiny cellular power plants called mitochondria. Each year about 50 Australian children inherit disorders of mitochondrial energy generation. The most severe disorders cause infant death, while others cause degenerative diseases in later life, particularly affecting brain and muscle. In most cases we lack effective treatments. The genetic causes of mitochondrial disorders are incredibly diverse, with over 70 disease genes known. Some are located on the uniqu ....Our bodies convert food into energy in tiny cellular power plants called mitochondria. Each year about 50 Australian children inherit disorders of mitochondrial energy generation. The most severe disorders cause infant death, while others cause degenerative diseases in later life, particularly affecting brain and muscle. In most cases we lack effective treatments. The genetic causes of mitochondrial disorders are incredibly diverse, with over 70 disease genes known. Some are located on the unique mitochondrial DNA we inherit only from our mothers. Many more genes await discovery. This grant focuses on the most common energy generation disorder, known as Complex I deficiency. Complex I requires 46 separate components to be assembled together in order to work properly, but mutations in the 46 genes encoding these components only seem to explain disease in about half of all patients. Our aim is to identify new disease genes and to determine whether some patients have mutations in two different genes that interact to cause disease, rather than in a single gene. We will use a number of methods to pinpoint where in the genome the causative genes are located and then home in on the exact changes in the genes that cause disease. Identifying these genes will allow us to improve future diagnosis and prevention of mitochondrial disease. We will also generate mice in which one of the Complex I genes has been knocked out. These mice will allow us to better understand the basic disease mechanisms that link gene changes to disease. Understanding the basic biology may allow us to develop new methods of treatment. The mouse models will also be useful for trialling new treatments and for investigating the role of milder mitochondrial problems in common diseases such as diabetes and Parkinson disease. Any new treatments could potentially have wide application.Read moreRead less
Detection Of Alternative Lengthening Of Telomeres In The Mouse
Funder
National Health and Medical Research Council
Funding Amount
$471,000.00
Summary
In each cell, DNA is packaged into units called chromosomes, the ends of which (i.e., telomeres) become slightly shorter every time they are replicated during the production of new cells. Continued cell replication and hence continued telomere shortening eventually results in the inability of cells to replicate themselves any further. Normal cells have mechanisms to slow down, but not completely prevent telomere shortening. The development of a cancer depends on its cells being able to replicate ....In each cell, DNA is packaged into units called chromosomes, the ends of which (i.e., telomeres) become slightly shorter every time they are replicated during the production of new cells. Continued cell replication and hence continued telomere shortening eventually results in the inability of cells to replicate themselves any further. Normal cells have mechanisms to slow down, but not completely prevent telomere shortening. The development of a cancer depends on its cells being able to replicate themselves many times, and therefore they need to find a method to prevent their telomeres shortening. We discovered one such method, called Alternative Lengthening of Telomeres (ALT), that is used by some cancers. It has been shown in principle that cancer cells can be killed by disrupting their ability to prevent telomere shortening. Therefore, in another project we are developing methods needed to find drugs that inhibit ALT. In the meantime, we have found the first evidence that some normal cells have an ALT-like mechanism. Our speculation is that cancer cells are able to dysregulate and subvert this normal mechanism in order to prevent their telomeres from shortening. In this project, we will analyse the ALT-like mechanism in mice, to determine its characteristics, and to determine what tissues use it. This information will provide critically important insights into the ALT mechanism itself, and the likely side effects of drugs that inhibit ALT.Read moreRead less
Genetic Models Of Cancer Development And Treatment
Funder
National Health and Medical Research Council
Funding Amount
$645,250.00
Summary
We are taking advantage of the powerful genetic tools in fruit flies to study the genetics of cancer. 72% of cancer genes are conserved between humans and fruit flies, making it a particularly suitable system. This project has two main aims: 1- to build tumours in fruit flies in an effort to understand better the individual genetic lesions that contribute to cancer It takes on average 4-7 mutations for a tumour to develop. While many genes associated with cancer have been identified, there are m ....We are taking advantage of the powerful genetic tools in fruit flies to study the genetics of cancer. 72% of cancer genes are conserved between humans and fruit flies, making it a particularly suitable system. This project has two main aims: 1- to build tumours in fruit flies in an effort to understand better the individual genetic lesions that contribute to cancer It takes on average 4-7 mutations for a tumour to develop. While many genes associated with cancer have been identified, there are many more that have not. What is more, it is still not clear precisely what mutations are responsible for a given tumour as tumours contain many genetic lesions most of which are incidental. We have a collection of fruit flies strains that represent various stages of the progress toward cancer development, and we intend to test different genetic combinations of these to determine which combinations result in cancer. 2- to identify a class of genes we have called 'oncogene suppressor genes' which may have the ability to prevent tumours from forming. Recently, it has been discovered that oncogenes may be required for both the INITIATION of tumours and the MAINTENANCE of tumours. This means that suppressing oncogene function may not only prevent tumour formation, but also tumour maintenance - in other words, it may make tumours go away. Thus, oncogene suppressor genes may represent exciting therapeutic targets for the treatment and possibly also prevention of cancer. At this time it is not clear whether oncogenes are generally required for tumour maintenance, or whether this is a property of only one or a few oncogenes. As these experiments are difficult and expensive to conduct in mammalian systems, we have devised simple, rapid tests in fruit flies instead. We plan to use these tests to investigate the effect of 'oncogene suppressor genes' on tumour initiation and maintenance in fruit flies. Ultimately, we believe these genes may represent therapeutic targets.Read moreRead less
Functions Of A Novel Conserved DNA Damage Response Protein Family In Telomere Stability
Funder
National Health and Medical Research Council
Funding Amount
$282,825.00
Summary
The free DNA ends of chromosomes, termed telomeres, generally resemble broken DNA. Because broken DNA is a major contributing factor to the onset of cancer, cells try to fix broken ends. However, in case of telomeres, such repair processes have to be prevented because otherwise different chromosomes would fuse with each other. Fused chromosomes are very fragile and cannot be evenly distributed between dividing cells, and are therefore another important trigger of cancer development. Therefore, c ....The free DNA ends of chromosomes, termed telomeres, generally resemble broken DNA. Because broken DNA is a major contributing factor to the onset of cancer, cells try to fix broken ends. However, in case of telomeres, such repair processes have to be prevented because otherwise different chromosomes would fuse with each other. Fused chromosomes are very fragile and cannot be evenly distributed between dividing cells, and are therefore another important trigger of cancer development. Therefore, chromosome ends are covered by a cap, which hides them from the DNA damage response machinery. From these considerations it is clear that there are close connections between the cellular DNA damage response and chromosome ends. Moreover, recently it has become clear that DNA damage proteins are also required to stop normal cells from growing, a process termed senescence. Senescence is a consequence of shortened chromosome ends, and does not occur in cancer cells. Altogether, it is clear that DNA breaks and senescence are two of the major questions for our understanding of cancer development. We have identified a novel conserved protein family that is involved in the response to DNA damage in yeast and humans. In addition, the yeast Mdt1 protein is a very sensitive indicator of changes in the telomere cap. Absence of proteins that organise the cap leads to the addition of several phosphate groups to the Mdt1 protein. We propose that phosphate-coupled Mdt1 prevents chromosome ends from fusion with each other, or from fusing with broken DNA ends after widespread damage. As a consequence, cells that have mild cap defects die at an >1000-fold increased rate in response to DNA damage when they also lack Mdt1. As part of this application we want to find out the precise mechanism by which Mdt1 stabilises chromosome ends, and test our hypothesis that the corresponding human protein termed ASCIZ also has similar functions in protecting chromosome ends.Read moreRead less
Structure and function of a new class of multi-zinc finger (MZF) transcriptional regulators. An understanding of how genes are switched on and off during the development and lifetime of an organism is central to developing the ability to fight many diseases in a rational way. This project will advance our knowledge in this area at a fundamental molecular level by examining the mechanisms through which a specific set of proteins controls gene expression.
I am a molecular geneticist with a primary focus on the identification of genes and sequence variants underlying susceptibility to, and progression of, various tumour types _ in particular tumours of the skin (moles and melanoma), oesophagus, ovary, lung